docs: def _transform_legacy_stats(self, stats):
          """Convert legacy stats to new stats with pools key."""
          # Fill pools for legacy driver reports
          if stats and 'pools' not in stats:
              pool = stats.copy()
              pool['pool_name'] = self.id
              for key in ('driver_version', 'shared_targets',
                          'sparse_copy_volume', 'storage_protocol',
                          'vendor_name', 'volume_backend_name'):
                  pool.pop(key, None)
              stats['pools'] = [pool]
          return stats